Utility companies such as power, water and natural gas providers typically maintain their facilities to a demarcation point (e.g., a meter) where the utility system interfaces with the customer location (e.g., an office, residence, etc.) Because telephone companies use call detail records (CDRs) to bill customers/subscribers for usage, telephone companies do not rely on meters as a demarcation point between customers and the public switched telephone network (PSTN). Instead, the telephone demarcation point is often located in an enclosure known in the art as a network interface device (NID). The NID is usually separated into a telephone company side and customer/subscriber side. The telephone company side of the NID often terminates in a modular jack (e.g., an RJ-11 jack) which a technician may plug into (e.g., with a loopback plug, test set, etc.) for testing and/or troubleshooting the telephone company wiring, for example back to a pedestal or central office. To connect the house or premises wiring (also known as inside wiring) to the telephone company wiring, a jumper cable terminated with a modular plug (e.g., an RJ-11 plug) is inserted into the aforementioned modular jack in the telephone company side of the NID. The other end of the jumper may be hardwired to the customer/subscriber inside wiring or, alternatively, may be terminated in another modular plug which plugs into a modular jack connecter in the customer/subscriber side of the NID. This configuration of modular jacks and jumpers in the NID allows the telephone company wiring and the inside wiring to be isolated from each other for attention to troubleshooting, repair and maintenance responsibilities.
Competition for local telephone service subscribers is growing. Broadband service providers such as cable providers offer digital telephone service, which turns voice calls into digital packets for communication over an IP network such as the internet. By provisioning head-end equipment, a broadband service provider can now offer cable TV service, telephone service and broadband data (i.e., Internet) service using one service drop.
When a cable subscriber elects to convert from standard telephone company-provided phone line (also known as twisted pair, “plain old telephone service” or POTS) to cable-provided phone service, the inside wiring is connected through a cable voice interface device to the cable provider's network. Typically, coaxial cable from the cable company terminates at a cable modem which is connected to a media terminal adapter (MTA). To interface the inside wiring with the cable company system or head end, the MTA is connected to a wall jack or other connection means (e.g., nailed connection, 66-block, etc) of the inside wiring. To isolate the cable equipment from the telephone company, the telephone company feed is disconnected from the inside wiring in the NID by, for example removing or disconnecting the aforementioned jumper at one or both ends.
The modular plug/modular jack/jumper configuration in the NID makes this disconnection/isolation a simple task for the customer or technician. However, a risk exists that, at some point in the future, the customer or a technician may reconnect a jumper to a now-empty modular jack. Cable voice interface devices may be then be exposed to potentially damaging signals from the telephone company feed. Similarly, signals from the MTA may cause damage to telephone company equipment, for example echo cancellers, digital cross connects and switches as the central office. One way to prevent reconnection is to remove the inside wiring from the NID and provide a new hard-wired connection or cross-connect from the inside wiring to the cable voice interface. However, this solution adds labor and equipment cost to the installation of the cable-provided phone service.
In view of the foregoing, an efficient apparatus for preventing the reconnection of a modular plug to a modular jack would be an important improvement in the art.